The present invention relates to a method and apparatus for a high resolution, short range navigation and tracking system utilizing phase lock loop technology.
Current ocean engineering and oceanographic survey and data collection procedures require precision position location with a high degree of repeatability. Typical applications include precision seismic profiling surveys, cable placement, narrow channel navigation, and precision location of open sea bench marks.
Radio navigation in its present form nearly exclusively relies upon phase discrimination of various incoming signals and/or time measurements of round trip travel for a pulse or pulse series. Systems such as Loran C, Decca, and Omega are considered state-of-the-art for global navigation and more recently for estuary and confluence navigation.
Studies have noted serious limitations in all of the above systems. Errors appear to compound at a staggering rate from causes such as operator ineptness, receiver misaligment, synchronization errors, geodetic and geometric irregularities, and multipath signal receiption. In all, these considerations provide for adequate open water navigation. However, operation becomes questionable in confined channel lanes and for high resolution surveys.
It is accordingly a general object of the invention to provide an improved short range precision navigation and tracking system.
It is a specific object of the invention to provide such a system utilizing phase lock loop technology.
It is still another object of the invention to provide a short range precision navigation and tracking system that employs conventional audio quality telemetry equipment and modular, off-the-shelf components to minimize cost and maximize effectiveness.
It is a feature of the navigation and tracking system that operator interaction is minimal.
It is a further feature of the system that the cost per meter of accuracy is apparently lower than other presently available systems.